Dr. Remy Hadley is the House M.D. character known by the nickname “Thirteen.”
Hadley joins House’s diagnostic team during the series’ fourth season after an unusually competitive hiring process. House frequently calls her “Thirteen” because she is identified by that number during the team-selection sequence. The nickname remains attached to her even after her identity becomes known to the other doctors.
The character is a medical doctor with a strong interest in diagnostic work, and her personal storyline includes Huntington’s disease. Her possible genetic risk and eventual diagnosis become important parts of the show’s later medical and emotional plotlines. She is portrayed by Olivia Wilde, whose performance made Thirteen one of the drama’s most recognizable later characters.
Viewers sometimes remember the nickname but overlook the surname because the show uses “Thirteen” so often. “Hadley” is her family name; Remy is her given name. This is separate from the actor’s name, Olivia Wilde, and from the number used to label her during the team auditions.